The Sixth Digit

Matthew pressed his thin frame into the mattress, trying to fold himself into the coarse weave of the sheets until he became a ghost in his own bed. The air in the room had turned tomb-cold, condensing his breath into thick white plumes that hung motionless in the dark. It wasn't the frost that locked his joints or sent his heart hammering against his ribs like a panicked bird in a cage; it was the sound. A rhythmic, deliberate rasp—the sound of soft human nails picking at the grain of the floorboards, searching for a seam. It crawled from the corner where the shadows pooled with unnatural density, inching toward the legs of his bed with agonizing patience. He squeezed his eyes shut until fractals of light burned against his eyelids, praying for a sensory hallucination or a waking fever. But the senses are honest witnesses. The scent of ancient rain, sharp with the tang of oxidized copper and wet silt, flooded his nostrils, making every breath a struggle against invisible weight. This smell was the herald, the precursor to the 'shifts' in this house—a structure that didn't merely house them, but seemed to absorb their heat and history into its stone marrow. When a pale, jaundiced…